I would like to A/B test newsletter practices - day/time sent, different styles, subject lines, etc. - but cannot figure out how to using Shopify Email. Ideally, there would be a way to generate two new random 50% segments upon request, but even if there were a more time-consuming way to do that once (e.g. sorting customers alphabetically by name and choosing every other one, or the bottom 50% vs the top 50%) that would be great. I found one suggestion to manually tag half the customers, but that is prohibitive even to do once.